Boeing Alert Requirements Bulletin 757-26A0062 RB: No revision named

Commercial Airplanes 757 Requirements Bulletin ALERT Number: 757-26A0062 RB Original Issue: January 17, 2025 ATA System: 2612 SUBJECT: FIRE PROTECTION - Engine Strut Overheat Detection - Strut Structure Inspection, Thermal Switches Functional Test and Precooler Replacement EXPORT CONTROLLED - This technology or software is subject to the U.S. Export Administration Regulations (EAR), (15 C.F.R. Parts 730-774). No authorization from the U.S. Department of Commerce is required for export, re-export, in-country transfer, or access EXCEPT to country group E:1 or E:2 countries/persons per Supp.1 to Part 740 of the EAR.

9E991ECCN:

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Table of Contents

1. EFFECTIVITY5

A. Airplanes5

B. Spares Affected7

2. CONCURRENT REQUIREMENTS7

3. COMPLIANCE7

4. APPROVAL9

5. ACCOMPLISHMENT INSTRUCTIONS .................................. 1 1 A. General Information ......................................... 1 1 B. Work Instructions ........................................... 1 3 FIGURE 1: LEFT AND RIGHT ENGINE NACELLE - LEFT AND RIGHT ENGINE STRUT STRUCTURE - INSPECTION .......................................... 1 6 FIGURE 2: LEFT AND RIGHT ENGINE NACELLE - PRECOOLER - REPLACEMENT [Group 2] . . . 18 APPENDIX A: THERMAL SWITCH TEMPERATURE LIMITS ........................ 2 0 Export Controlled ECCN: 9E991 See page 1 for details Original Issue: January 17, 2025 757-26A0062 RB 3 of 20 REQUIREMENTS BULLETIN 757-26A0062

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Commercial Airplanes 757 Requirements Bulletin ALERT Number: 757-26A0062 RB Original Issue: January 17, 2025 ATA System: 2612 SUBJECT: FIRE PROTECTION - Engine Strut Overheat Detection - Strut Structure Inspection, Thermal Switches Functional Test and Precooler Replacement

THIS DOCUMENT IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE NEW OWNER. THIS IS AN ENHANCED REQUIRED FOR COMPLIANCE DOCUMENT. THE BOEING

PROCESSES USED TO CREATE THE SERVICE BULLETIN (SB) AND THE REQUIREMENTS BULLETIN (RB) ENSURE THAT THE INFORMATION BETWEEN "RC START" AND "RC END" IN THE SB ARE IDENTICAL TO THE INFORMATION IN THE SAME SECTIONS (COMPLIANCE, WORK INSTRUCTIONS…) OF THE RB WHICH THE SB REFERS TO AS THE RELATED DOCUMENT.

1. Effectivity A. Airplanes This bulletin is applicable to 757-200, 757-200CB, 757-200PF, 757-300 Airplane(s), line number(s) 2-36, 38, 40, 42, 50-52, 54, 56-58, 63, 74-81, 89-90, 93-94, 96-100, 102, 114-117, 123, 125, 127, 130, 132, 142, 144-146, 148, 150-153, 155-156, 160-163, 165-170, 172-175, 178-180, 182-183, 185, 187, 200, 203-204, 208-215, 218-221, 224-228, 232-234, 236-237, 240, 242-245, 248-250, 252-253, 255-260, 262, 268-269, 271-273, 276, 278-283, 288-289, 292, 296-297, 302-304, 308-309, 314-317, 321, 323-325, 327-328, 332-333, 336-337, 340, 344-345, 350-351, 356-360, 362-365, 368, 370-371, 374-375, 378-379, 383-384, 387-392, 397-398, 400, 402, 404, 409-410, 412, 417-418, 423, 425, 432-433, 436, 440-441, 445, 449-453, 457, 459-461, 463, 466, 468, 470-476, 478, 480, 482-484, 486, 491, 495, 503-504, 507, 509, 511, 514, 517, 519-520, 522-523, 525-526, 528-530, 534, 536, 538, 540, 544-549, 551-555, 557, 561-562, 564-566, 568, 572, 574-575, 578, 580, 582-586, 589, 593, 595-596, 598, 600-625, 627-638, 640-666, 668-683, 685-687, 690-692, 694, 698, 702, 704, 706-708, 712, 717, 720, 722-723, 725-726, 728-730, 733-735, 737-738, 745-749, 751-753, 755-756, 759, 761-763, 765-769, 771, 774, 776, 778-782, 784, 786, 788, 790-791, 793, 795-799, 802, 804-806, 809-818, 822-823, 827-828, 830, 833-834, 837, 839-840, 842-843, 846-853, 855-856, 858-868, 870-873, 877, 879, 881-882, 888-889, 894-895, 897, 899-900, 902-903, 905-906, 909, 911-913, 915-916, 918-920, 922-926, 928-933, 935-936, 938, 940, 943, 945-948, 950-952, 956, 958, 960-967, 969-970, 972-974, 976-981, 983-986, 988-1000, 1002-1005, 1007-1009, 1012, 1015, 1017-1018, 1026, 1028-1029, 1031-1032, 1038-1043, 1047-1048 in 2 Group(s). Where the effectivity is presented with hyphens between line numbers, the airplane applicability means "through" and "inclusive", e.g. line numbers 1-9 means line numbers 1 through 9 inclusive.

The Variable Numbers and Group Information for the applicable airplanes is given below.

Export Controlled ECCN: 9E991 See page 1 for details Original Issue: January 17, 2025 757-26A0062 RB 5 of 20

DESCRIPTIONCONFIGURATIONGROUP 757-200, 757-200CB, 757-200PF airplanes that have RB211-535 engines installed.

-1 757-300 airplanes that have RB211-535 engines installed.-2 Airplane Models:

757-200, 757-200CB, 757-200PF, 757-300 GroupVariable Number 1NA002 - NA028 1NA191 - NA199 1NA201 - NA239 1NA301 - NA305 1NA341 - NA352 1NA391 - NA399 1NA401 - NA408 1NA441 - NA447 1NB021 - NB023 1NB036 - NB041 1NB051 - NB053 1NB061 - NB073 1NB079 1NB131 - NB148 1NB161 - NB162 1NB201 - NB204 1NB221 - NB228 1NB230 1NB236 1NB239 1NB261 - NB267 1NB291 - NB299 1NB301 - NB302 1NB311 - NB312 GroupVariable Number 1NB321 - NB331 1NB421 - NB438 1NB446 1NB451 - NB454 1NB501 - NB523 1NB561 1NB571 1NB581 - NB583 1NC058 - NC062 1NC936 - NC950 1NC971 - NC974 1ND001 - ND007 1ND011 - ND059 1ND111 - ND113 1ND161 - ND199 1ND201 - ND203 1ND221 - ND225 1ND241 - ND248 1ND301 - ND322 1ND401 1ND891 1ND895 1NJ001 - NJ004 1NJ031 - NJ032 GroupVariable Number 2NL001 - NL002 2NL006 - NL017 2NL101 - NL109 2NL141 1NN001 - NN002 1NN051 - NN052 1NS601 - NS616 1NT001 - NT009 1NT201 - NT202 1NT231 - NT234 1NT237 - NT240 1NT242 1NT245 - NT248 1NT281 - NT289 1NT381 - NT386 1NT401 - NT409 1NT411 - NT412 1NT426 - NT427 1NT431 - NT432 1NT436 - NT438 1NT446 1NT731 - NT769 1NT861 - NT862 1NT901 - NT916 Export Controlled ECCN: 9E991 See page 1 for details Original Issue: January 17, 2025 757-26A0062 RB 6 of 20 REQUIREMENTS BULLETIN 757-26A0062

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GroupVariable Number 1NT971 - NT985 2NU701 - NU705 GroupVariable Number 2NU721 - NU728 2NU731 - NU732 GroupVariable Number -- -- B. Spares Affected None.

2. CONCURRENT REQUIREMENTS None.

3. COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to Requirements Bulletin 757-26A0062 RB. The Airworthiness Directive will make the compliance tasks and times given in Requirements Bulletin 757-26A0062 RB mandatory.

When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for that CONDITION or OPTION.

Accomplish the required action(s), based on the applicable condition(s) in Table(s) 1, 2 and 3, in accordance with Accomplishment Instructions.

Table 1: Left and Right Engine Strut Structure General Visual Inspection Repeat Interval (Not to Exceed) Boeing Recommended Compliance Time ActionCondition -Within 6 months after the Original Issue date of Requirements Bulletin 757- 26A0062 RB.

Do a General Visual Inspection (GVI) for indication of heat damage on the top side of the left and right engine strut structure, upper spar web and the internal strut box structure. (a) All Airplanes --No further action is required.

CONDITION 1:

NO INDICATION OF HEAT

DAMAGE FOUND -Before further flight.

Contact the Boeing Company for repair instructions and do the repair.

CONDITION 2:

ANY INDICATION OF

HEAT DAMAGE FOUND

(a) Heat damage indication is defined by discoloration and blistering of the primer and/or paint on the left and right engine strut structure, upper spar web and the internal strut box structure in the area of the precooler. Refer to APPENDIX E in service bulletin 757- 26A0062 for heat damage examples.

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Table 2: Left and Right Engine Strut Thermal Switch Temperature and Continuity Tests Repeat Interval (Not to Exceed) Boeing Recommended Compliance Time (Whichever Occurs First) ActionCondition -Within 27 months after the Original Issue date of Requirements Bulletin 757- 26A0062 RB.

Within 9,000 flight hours after the Original Issue date of Requirements Bulletin 757- 26A0062 RB.

Do the thermal switch temperature test and do the continuity test of the ground wires.(a) All Airplanes 8,000 Flight Hours.--Repeat the thermal switch temperature test and the continuity test of the ground wires.(a) CONDITION 3:

THERMAL SWITCH TEM-

PERATURE TEST WITHIN

LIMITS AND CONTINUITY TEST PASSED.

-Before further flight.ACTION 1:CONDITION 4:

Replace any failed thermal switch with a new thermal switch.

THERMAL SWITCH TEM-

PERATURE TEST NOT

WITHIN LIMITS OR CON- TINUITY TEST FAILED. -Before further flight.ACTION 2:

Repair or replace any open circuit wires found to have failed the continuity test.

-Before further flight.ACTION 3:

Do a System Test-Strut Overheat Detection System. If the test fails, do applicable corrective action(s) and repeat the test until the test passes.

8,000 Flight Hours.--ACTION 4:

Repeat the thermal switch temperature test and the continuity test of the ground wires.(a)

(a) Thermal switch temperature limits are specified in Appendix A table.

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Group 2:

Table 3: Precooler Replacement Repeat Interval (Not to Exceed) Boeing Recommended Compliance Time (Whichever Occurs Later) ActionCondition -Within 9,000 flight hours or 27 months, whichever occurs first, after the Original Issue date of Requirements Bulletin 757- 26A0062 RB.

Before 45,000 total precooler Flight Hours.

ACTION 1:

Replace the precooler with a new or serviceable precooler. (a) Airplanes where the precooler Flight Hours can be determined.

45,000 total precooler Flight Hours.

--ACTION 2:

Repeat replacement of the precooler with a new or serviceable precooler.

(a) -Within 9,000 flight hours or 27 months, whichever occurs first, after the Original Issue date of Requirements Bulletin 757- 26A0062 RB.

-ACTION 1:

Replace the precooler with a new or serviceable precooler. (a) Airplanes where the precooler Flight Hours cannot be determined.

45,000 total precooler Flight Hours.

--ACTION 2:

Repeat replacement of the precooler with a new or serviceable precooler.

(a)

(a) A serviceable precooler is either a unit with less than 45,000 total precooler flight hours or has less than 45,000 precooler flight hours since the last recore, refer to Honeywell Service Information Letter (SIL) D202003000632 R01 for additional information.

4. APPROVAL This Requirements Bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this document comply with the applicable regulations and are FAA approved, as well as European Union Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in this Requirements Bulletin effectivity. This document and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other Boeing changes.

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If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this Requirements Bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this Requirements Bulletin.

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5. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION

KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED

MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE.

CAUTION NOTE: 1. This is an Enhanced Required for Compliance document. There will be a separate Service Bulletin (SB) and a separate Requirements Bulletin (RB). If an RB is mandated by an Airworthiness Directive (AD), then all applicable requirements specified in the RB must be done. For the related SB, some locations are marked RC Start and RC End to identify the requirements that are restated from the RB. For the related SB, the areas between RC Start and RC End, including sub-steps and any figures identified between RC Start and RC End, must be done to comply with the AD.

Therefore, an Alternative Method of Compliance (AMOC) is required for any deviations to steps between RC Start and RC End, including substeps and identified figures.

For the related SB, the steps not between RC Start and RC End may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC; this is provided that the steps between RC Start and RC End, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition.

Figures not required for compliance are omitted from the RB.

2. This is an Enhanced Required for Compliance document. The Boeing processes used to create the Service Bulletin (SB) and the Requirements Bulletin (RB) ensure that the information between "RC Start" and "RC End" in the SB are identical to the information in the same sections (Compliance, Work Instructions...) of the RB which the SB refers to as the related document.

3. The compliance times for the actions in WORK INSTRUCTIONS are in Compliance.

4. Boeing Service Letter 757-SL-51-022, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided.

5. Unless shown differently, these dimensions and tolerances are used:

– Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque Values:

— Values for structural fasteners are given in 757 Structural Repair Manual, Chapter 51.

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— Values for airframe maintenance tasks are included in Chapter 20 of 757 Aircraft Maintenance Manual (AMM).

— Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM).

— Values for engine maintenance tasks are included in Chapter 70 of 757 Aircraft Maintenance Manual (AMM).

— Non-standard torque values for maintenance tasks are included in the applicable installation step.

6. These work instructions refer to procedures included in other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used.

7. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed.

8. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity.

This level of inspection is made from within touching distance, unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked. Basic cleaning may be required to ensure appropriate visibility.

9. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for that CONDITION or OPTION.

10. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures, and SWPM 20-10-19 for the wire separation requirements, as accepted procedures.

11. A serviceable precooler is either a unit with less than 45,000 total precooler flight hours or has less than 45,000 precooler flight hours since the last recore, refer to Honeywell Service Information Letter (SIL) D202003000632 R01 for additional information.

12. Heat damage indication is defined by discoloration or blistering of the primer or paint on the left and right engine strut structure, upper spar web and the internal strut box structure in the area of the precooler. Refer to APPENDIX E in service bulletin 757-26A0062 for heat damage examples.

13. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200.

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